CVE-2026-30871 (GCVE-0-2026-30871)
Vulnerability from cvelistv5 – Published: 2026-03-19 21:49 – Updated: 2026-03-25 03:56
VLAI?
Title
OpenWrt Project has Stack-based Buffer Overflow in DNS PTR Query
Summary
OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the parse_question function. The issue is triggered by PTR queries for reverse DNS domains (.in-addr.arpa and .ip6.arpa). DNS packets received on UDP port 5353 are expanded by dn_expand into an 8096-byte global buffer (name_buffer), which is then copied via an unbounded strcpy into a fixed 256-byte stack buffer when handling TYPE_PTR queries. The overflow is possible because dn_expand converts non-printable ASCII bytes (e.g., 0x01) into multi-character octal representations (e.g., \001), significantly inflating the expanded name beyond the stack buffer's capacity. A crafted DNS packet can exploit this expansion behavior to overflow the stack buffer, making the vulnerability reachable through normal multicast DNS packet processing. This issue has been fixed in versions 24.10.6 and 25.12.1.
Severity ?
CWE
- CWE-121 - Stack-based Buffer Overflow
Assigner
References
| URL | Tags | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||
Impacted products
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-30871",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-24T00:00:00+00:00",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T03:56:12.627Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "openwrt",
"vendor": "openwrt",
"versions": [
{
"status": "affected",
"version": "\u003c 24.10.6"
},
{
"status": "affected",
"version": "\u003e= 25.12.0-rc1, \u003c 25.12.1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the parse_question function. The issue is triggered by PTR queries for reverse DNS domains (.in-addr.arpa and .ip6.arpa). DNS packets received on UDP port 5353 are expanded by dn_expand into an 8096-byte global buffer (name_buffer), which is then copied via an unbounded strcpy into a fixed 256-byte stack buffer when handling TYPE_PTR queries. The overflow is possible because dn_expand converts non-printable ASCII bytes (e.g., 0x01) into multi-character octal representations (e.g., \\001), significantly inflating the expanded name beyond the stack buffer\u0027s capacity. A crafted DNS packet can exploit this expansion behavior to overflow the stack buffer, making the vulnerability reachable through normal multicast DNS packet processing. This issue has been fixed in versions 24.10.6 and 25.12.1."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "HIGH",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 9.5,
"baseSeverity": "CRITICAL",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "HIGH",
"subConfidentialityImpact": "HIGH",
"subIntegrityImpact": "HIGH",
"userInteraction": "NONE",
"vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-121",
"description": "CWE-121: Stack-based Buffer Overflow",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-19T21:49:50.876Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/openwrt/openwrt/security/advisories/GHSA-7c3j-f7w2-p8f6",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/openwrt/openwrt/security/advisories/GHSA-7c3j-f7w2-p8f6"
},
{
"name": "https://github.com/openwrt/openwrt/releases/tag/v24.10.6",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/openwrt/openwrt/releases/tag/v24.10.6"
},
{
"name": "https://github.com/openwrt/openwrt/releases/tag/v25.12.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/openwrt/openwrt/releases/tag/v25.12.1"
}
],
"source": {
"advisory": "GHSA-7c3j-f7w2-p8f6",
"discovery": "UNKNOWN"
},
"title": "OpenWrt Project has Stack-based Buffer Overflow in DNS PTR Query"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-30871",
"datePublished": "2026-03-19T21:49:50.876Z",
"dateReserved": "2026-03-06T00:04:56.698Z",
"dateUpdated": "2026-03-25T03:56:12.627Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-30871\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-03-19T22:16:31.633\",\"lastModified\":\"2026-03-24T14:07:06.507\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the parse_question function. The issue is triggered by PTR queries for reverse DNS domains (.in-addr.arpa and .ip6.arpa). DNS packets received on UDP port 5353 are expanded by dn_expand into an 8096-byte global buffer (name_buffer), which is then copied via an unbounded strcpy into a fixed 256-byte stack buffer when handling TYPE_PTR queries. The overflow is possible because dn_expand converts non-printable ASCII bytes (e.g., 0x01) into multi-character octal representations (e.g., \\\\001), significantly inflating the expanded name beyond the stack buffer\u0027s capacity. A crafted DNS packet can exploit this expansion behavior to overflow the stack buffer, making the vulnerability reachable through normal multicast DNS packet processing. This issue has been fixed in versions 24.10.6 and 25.12.1.\"},{\"lang\":\"es\",\"value\":\"El Proyecto OpenWrt es un sistema operativo Linux dirigido a dispositivos embebidos. En versiones anteriores a la 24.10.6 y 25.12.1, el demonio mdns tiene una vulnerabilidad de desbordamiento de b\u00fafer basado en pila en la funci\u00f3n parse_question. El problema se activa por consultas PTR para dominios DNS inversos (.in-addr.arpa y .ip6.arpa). Los paquetes DNS recibidos en el puerto UDP 5353 son expandidos por dn_expand en un b\u00fafer global de 8096 bytes (name_buffer), que luego se copia mediante un strcpy sin l\u00edmites en un b\u00fafer de pila fijo de 256 bytes al manejar consultas TYPE_PTR. El desbordamiento es posible porque dn_expand convierte bytes ASCII no imprimibles (p. ej., 0x01) en representaciones octales de m\u00faltiples caracteres (p. ej., \\\\001), inflando significativamente el nombre expandido m\u00e1s all\u00e1 de la capacidad del b\u00fafer de pila. Un paquete DNS manipulado puede explotar este comportamiento de expansi\u00f3n para desbordar el b\u00fafer de pila, haciendo que la vulnerabilidad sea alcanzable a trav\u00e9s del procesamiento normal de paquetes DNS multicast. Este problema ha sido corregido en las versiones 24.10.6 y 25.12.1.\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":9.5,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"HIGH\",\"subConfidentialityImpact\":\"HIGH\",\"subIntegrityImpact\":\"HIGH\",\"subAvailabilityImpact\":\"HIGH\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":9.8,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-121\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:openwrt:openwrt:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"24.10.6\",\"matchCriteriaId\":\"12B5818C-BB4D-4486-9C53-7FCA8EF2EDA8\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:openwrt:openwrt:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"25.12.0\",\"versionEndExcluding\":\"25.12.1\",\"matchCriteriaId\":\"061FA3CA-10C0-4EF2-8566-E623964CAE79\"}]}]}],\"references\":[{\"url\":\"https://github.com/openwrt/openwrt/releases/tag/v24.10.6\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/openwrt/openwrt/releases/tag/v25.12.1\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/openwrt/openwrt/security/advisories/GHSA-7c3j-f7w2-p8f6\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Vendor Advisory\"]}]}}",
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-30871\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-20T20:15:57.625790Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-20T20:16:04.477Z\"}}], \"cna\": {\"title\": \"OpenWrt Project has Stack-based Buffer Overflow in DNS PTR Query\", \"source\": {\"advisory\": \"GHSA-7c3j-f7w2-p8f6\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 9.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"CRITICAL\", \"vectorString\": \"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"HIGH\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"HIGH\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"HIGH\", \"vulnConfidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"openwrt\", \"product\": \"openwrt\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 24.10.6\"}, {\"status\": \"affected\", \"version\": \"\u003e= 25.12.0-rc1, \u003c 25.12.1\"}]}], \"references\": [{\"url\": \"https://github.com/openwrt/openwrt/security/advisories/GHSA-7c3j-f7w2-p8f6\", \"name\": \"https://github.com/openwrt/openwrt/security/advisories/GHSA-7c3j-f7w2-p8f6\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/openwrt/openwrt/releases/tag/v24.10.6\", \"name\": \"https://github.com/openwrt/openwrt/releases/tag/v24.10.6\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/openwrt/openwrt/releases/tag/v25.12.1\", \"name\": \"https://github.com/openwrt/openwrt/releases/tag/v25.12.1\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the parse_question function. The issue is triggered by PTR queries for reverse DNS domains (.in-addr.arpa and .ip6.arpa). DNS packets received on UDP port 5353 are expanded by dn_expand into an 8096-byte global buffer (name_buffer), which is then copied via an unbounded strcpy into a fixed 256-byte stack buffer when handling TYPE_PTR queries. The overflow is possible because dn_expand converts non-printable ASCII bytes (e.g., 0x01) into multi-character octal representations (e.g., \\\\001), significantly inflating the expanded name beyond the stack buffer\u0027s capacity. A crafted DNS packet can exploit this expansion behavior to overflow the stack buffer, making the vulnerability reachable through normal multicast DNS packet processing. This issue has been fixed in versions 24.10.6 and 25.12.1.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-121\", \"description\": \"CWE-121: Stack-based Buffer Overflow\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-03-19T21:49:50.876Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-30871\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-03-25T03:56:12.627Z\", \"dateReserved\": \"2026-03-06T00:04:56.698Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-03-19T21:49:50.876Z\", \"assignerShortName\": \"GitHub_M\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…